225 Pa. Code § 1004 : — RULES OF EVIDENCECONTENTS OF WRITINGS, RECORDINGS, AND PHOTOGRAPHS — Admissibility of Other Evidence of Content

An original is not required and other evidence of the content of a writing, recording, or photograph is admissible if:

(a) all the originals are lost or destroyed, and not by the proponent acting in bad faith;
(b) an original cannot be obtained by any available judicial process;
(c) the party against whom the original would be offered had control of the original; was at that time put on notice, by pleadings or otherwise, that the original would be a subject of proof at the trial or hearing; and fails to produce it at the trial or hearing; or
(d) the writing, recording, or photograph is not closely related to a controlling issue.

225 Pa. Code § 1004